Ship salvaging apparatus and method



April 24, 1962 J. J. METZGER SHIP SALVAGING APPARATUS AND METHOD FiledNov. 26, 1957 4 Sheets-Sheet 1 INVENTOR JOHN J. METZGER ATTORNEYS April24, 1962 J. J. METZGER SHIP SALVAGING APPARATUS AND METHOD 4Sheets-Sheet 2 Filed NOV. 26, 1957 INVENTOR.

JOHN J. METZGER BMW M 14 ATTORNEYS April 24, 1962 J. J. METZGER' SHIPSALVAGING APPARATUS AND METHOD 4 Sheets-Sheet 3 Filed NOV. 26, 195'? INVENTOR.

JOHN J. METZGER ATTORNEYS Aprll 24, 1962 J. J. METZGER SHIP SALVAGINGAPPARATUS AND METHOD 4 Sheets-Sheet 4 Filed NOV. 26, 1957 R R E 0 O G mm U n W- M m J m" N H 0 V a. F ww T w A a A K mm .5 0m \H V J VLU \IV VL mm 5 5 pm v9 00. N9 mm mm 3 m9 mm N9 mm mm vw m9 ATTORNEYS UnitedStates ate 3,@3@,95 Patented Apr. 24, 1962 ice 3,030,965 SHIP SALVAGINGAPPARATUS AND METHOD John J. Metzger, 5198. 2nd St., Lindenhurst, N .Y.Filed Nov. 26, 1957, Ser. No. 699,001 24 Claims. (Cl. 114-55) Thisinvention relates to a method of and an apparatus for salvaging largeheavy objects such as ships lying below the water. The invention isparticularly useful in, although it is not restricted to, the salvagingof large ships sunk in deep water at a depth beyond that at which diversmay normally work for an extended period.

The invention has among its objects the provision of a novel method ofsalvaging objects sunk in the water.

Another object of the invention lies in the provision of a novel rig forwater salvaging operations.

Yet another object of the invention resides in the provision of a novelmethod of and an apparatus for salvaging sunken objects substantiallywithout or totally without the use of divers.

Still another object is the provision of a salvage rig for use in watersalvaging operations which may be left without risk of damage andwithout the loss of any substantial amount of work in the event of astorm, and with which the salvage work may immediately be picked upagain when the storm has subsided.

A further object of the invention resides in the provision of novelsalvaging apparatus which is simple, economical to assemble and operate,and is rugged and trouble-free in operation.

A further object of the invention resides in the provision of salvagingapparatus wherein the various parts thereof are under complete controlat all stages of the salvaging operation.

Still another object lies in the provision of salvaging apparatus whichis eflicient in breaking the object to be salvaged free from the mud orsilt in which it may lie at the bottom of the water.

Still another object of the invention lies in the provision of animproved drawline and/or lifting cable or chain laying device.

Yet another object of the invention resides in the provision of animproved trench-forming device, in the specific apparatus shown suchtrench-forming device forming a part of the line or cable layingapparatus.

Other objects of the invention include the provision of a novelobject-lifting device, a novel agitator means associated with thelifting device for aiding in the breaking of the object free from themud or silt at the bottom of the water, and a novel remotelycontrollable, adjustable connecting mechanism between object-liftingdevices and the lifting cables or chains which partially embrace theobject to be lifted.

The above and further objects and novel features of the invention willmore fully appear from the following description when the same is readin connection with the accompanying drawings. It is to be expresslyunderstood, however, that the drawings are for the purpose ofillustration only and are not intended as a definition of the limits ofthe invention.

In the drawings, wherein like reference characters refer to like partsthroughout the several views,

FIG. 1 is a somewhat schematic view in plan of a sunken ship to besalvaged, the figure showing an intermediate position in the assembly ofthe salvaging rig;

FIG. 2 is a schematic view in perspective of the salvaging rig assemblyin substantially completed condition, the distance from the surface ofthe Water to the ship being greatly foreshortened for clarity ofillustration;

'FIG. 3 is a view in front elevation of the ship in righted andintermediate lifted position, additional or alternative lifting buoys orpontoons which may be employed in the lifting process being shown inphantom lines, the illustration of the surface elements of the rig beingsimplified;

FIG. 4 is a view in side elevation with the ship lifted to lie on thesurface of the water and with the hole in the hull of the shiptemporarily patched;

FIG. 5 is a view in side elevation of a preferred form of drawline and/or lifting cable or chain-laying apparatus, such apparatus including atrench-forming tool;

FIG. 6 is a view in transverse section through the cable-layingapparatus of FIG. 5, the section being taken generally along the line6-6 of FIG. 5;

FIG. 7 is an enlarged fragmentary view in longitudinal axial sectionthrough the cable-laying apparatus, the view being taken adjacent thetransverse central portion of the apparatus;

FIG. 8 is an enlarged view in transverse section through one of thedrawline storing and dispensing guide means disposed along the length ofthe trench-forming tool in the apparatus of FIGS. 5, 6, and 7;

FIG. 9 is a view in side elevation of a shoe or runner which forms apart of the cable or chain-laying means of the apparatus of FIGS. 5, 6,and 7;

FIG. 10 is a view in side elevation of a lifting device in the form of apontoon or buoy, a portion of the pontoon intermediate the lengththereof being broken away for economy of space, the wall of the pontoonbeing broken through at the water inlet and exhaust port, the wall ofthe pontoon being additionally broken through at the passagetherethrough receiving the lifting means such as a chain or cable,portions of the lifting chains and the agitating hoses disposed aboutthe portions. of the chains below the pontoons being fragmentarilyshown; and

FIG. 11 is a fragmentary view in side elevation of a lifting chainemployed in the apparatus shown in FIG. 10, FIG. 11 showing theoperating mechanism for the latching dogs on the chain, the dogs beingshown in inoperative position, that is, lying along the length of thechain.

The salvaging method and apparatus of the present invention areillustrated herein in connection with the raising of a large ocean linersunk in deep water which, for purposes of illustration, is assumed toexceed in depth that at which divers may safely operate for extendedperiods. The present invention, as apparent from above, is designed toeliminate or substantially eliminate the use of divers, thereby markedlydecreasing the hazards of the salvaging operation.

Since the salvaging method and apparatus of the invention require nodivers, at least after brief explorations of the object to be salvaged,the site of the salvaging operation can be left at almost any time bythe surface vessels and personnel, after a minimum of operationsnecessary to secure the parts at the surface, since there is no problemof returning divers to the surface. Thus the rig may be quickly left,for example, when a storm of such force arises that it would beinadvisable to continue salvaging operations at that time. The salvagingrig of the invention is of such character that the salvaging operationsmay quickly be resumed upon the return of the surface vessels andpersonnel to the site. At each stage of the salvaging operations, fromthe initial placement of the main parts thereof to the lifting of theobject to be salvaged, the various parts of the rig are under completecontrol at one or more stations at the surface of the water.

Proceeding now to a consideration of the drawings, there is shown inFIGS. 1 and 2 a large ship such as an ocean liner designated 10, lyingon the bottom 11 of the ocean. The water above the ship is designated12, and

the surface of the water by the character 14. The particular ship shownis one that has been sunk by an accident which resulted in the formationof a large hole 15 in a side thereof. For the purpose of description, itwill be assumed that the bottom 11 lies at a comparatively greatdistance, on the order of 200 feet or more, below the surface, althoughit will be appreciated that the method and apparatus of the inventiondisplay great advantages in salvaging operations conducted at lessdepths.

In starting the salvaging operation, after the ship has been located, itis convenient to outline the ship by the series of small locating buoysconnected by cables to magnetic grappling devices which attachthemselves to the ship. For the purpose of simplification, such locatingbuoys and magnetic grappling devices are not shown in the drawings. Itwill be understood, however, that the ship may be outlined at thesurface of the water in other manners. After the ship has been locatedand outlined, two laterally spaced main forward buoys 16 and two aftbuoys 17 are now located at positions somewhat forwardly of andrearwardly of, repectively, the bow and stern of the ship. Buoys 16 and17 may be secured in position by anchor lines, of which typical ones areindicated at 19. The respective buoys 16 and 17 are now connected byprimary or longitudinal bridle cables 20, and the pairs of buoys 16 and'17 are connected a shown by transverse bridle cables 21 and 21. Theplacing of the buoys 16 and 17 and the bridle cables, as described, maybe conveniently carried out by small surface, tender vessels 22. Thebuoys 16, 17 and the longitudinal and transverse bridle cables not onlyserve to outline the site of the ship, but also function as the means atthe surface of the water supporting the upper ends of the drawlines and/or ship-raising or lifting devices in the assembly of the salvaging rig.

A cable-laying apparatus or tool 24 is now sunk to the bottom of theocean in a location somewhat forwardly of or rearwardly of, as the casemay be, the bow or the stern of the ship. In the assembly illustrated inFIG. 1, the apparatus 24 has been sunk forwardly of the bow of thevessel. Apparatus 24, which will be described more fully in connectionwith FIGS. -9, inclusive, is in the form of a laterally symmetricalbroad general V-shaped conduit which is of such breadth and depth as toembrace the lower part of the ship to be salvaged while having thebranches or legs of the apparatus substantially spaced beneath andlaterally of the ship. Apparatus 24 includes a tunnel or trench-formingdevice supplied with fluid, preferably water, under pressure; thetrench-forms ing device is so constructed and arranged as to dredge atrench or passage beneath the vessel as the tool is moved longitudinallyof the ship. Apparatus 24 is provided with one or more drawlines and/orlifting cable or chainlaying devices, so that the drawlines and/orlifting devices may be deposited or drawn in, respectively, beneath theship and left at positions spaced longitudinally of the ship as theapparatus 24 travels therealong. For the purpose of simplicity ofillustration, in FIGS. 1 and 2 of the drawing the elongated flexiblemeans designated 31, which are shown in FIG. 1 as having been depositedby the apparatus 24, are assumed to be the actual lifting devices suchas chains or cables. As will appear in connection with FIGS. 6 and 7,however, the flexible members deposited beneath the ship initially maybe drawlines, the actual lifting devices being subsequently drawn intoplace around the ship.

The ends of the thus deposited drawlines and/ or lifting devices 31 aresecured to the portion of the salvaging rig which lies at the surface ofthe water. For this purpose there are preferably provided two secondarybridle members 30 and 30 which are secured between the traverse bridles21, 21 and lie parallel to longitudinal bridles 20 but inwardly thereof,preferably somewhat laterally outwardly of the sides of the ship. Theends of lifting members 31 are shown attached to the secondary bridlemembers at 32 and 32. Although for the sake of simplicity only onelifting member 31 is shown at each location, and such locations arewidely spaced, it will be apparent from FIG. 2 that a large number oflifting devices will be employed. Preferably the means attaching thelifting devices 31 to the secondary bridles are in the form of clamps,whereby the lifting devices may be taken up and re-clamped on thesecondary bridles as the ship is gradually lifted. It will be understoodthat a substantial length of each end of lifting device 31 will be leftextending beyond the secondary bridle, particularly on the high side ofthe ship, if the latter lies in tipped position.

In the embodiment shown, the apparatus 24 is symmetrically supplied withfluid, preferably water, under pressure, from both ends thereof.Flexible multiple supply hose devices 25 are connected between therespective ends of apparatus 24 and two tenders 22, as shown in FIG. 1.The tenders 22 move with the apparatus 24, so as to supply dredgingfluid under pressure thereto and to serve as stations from which to drawin or deposit the drawlines and/or lifting devices beneath the ship 10.Apparatus 24 may be drawn progressively along and beneath the ship 10 bymeans of draw cables 26 which are attached at one end to terminalmembers 40 of the tool by means of suitable eye members 29 thereon, thedraw cables running over suitable pulley devices 27 on the transversebridle 21 and being drawn in by suitable winching means on therespective tenders 22. The tenders 22 will themselves be propelled asrequired to travel with apparatus 24. Thus, in the embodiment shown, thetenders 22, which carry pumping and valve devices (not shown) to supplymultiple hoses 25, move progressively along the sides of the location ofthe ship 10, and by their winching devices, progressively pull in thedraw cables 26 to cause apparatus 24 to move longitudinally beneath ship10.

After the apparatus 24 has made a complete pass beneath the ship 10, andhas laid drawlines and/or lifting devices at spaced intervals in suchtravel, the apparatus 24 and its traversing and fluid supply means maybe removed from the site of the salvaging operations. If only drawlineswere initially laid beneath the ship, the lifting devices, such ascables or chains, are now drawn into place and are secured at their endsto the surface rig in the manner shown in FIG. 2. Thereupon liftingpontoons 34 are attached to the lifting devices 31. In the arrangementshown, each of the pontoons 34 is adjustably secured to a set of threelifting devices 31. In mounting the particular pontoons shown, the upperends of one run of lifting devices 31 are removed from their respectivesecondary bridle, the pontoon is installed on the lifting cables orchains, the pontoon is lowered along the lifting devices to the leveldesired, and the upper ends of such runs of the lifting devices arereattached to the secondary bridle. Consequently, such lifting devicesremain available for the attachment of additional lifting pontoons orthe removal of the pontoons already assembled thereon at any time. Aftera sufficient number of pontoons 34 have been initially mounted upon thelifting devices 31 at each side of ship 10, the pontoons are givensuflicient buoyancy, by the blowing of a part of the water therefrom, tostart the raising of the ship. If the ship has become embedded to asubstantial extent in mud or silt on the bottom, the initial freeing ofthe ship from the bottom may be facilitated by agitating means, such asthose shown in FIG. 10, disposed about the lower portion of the liftingdevices beneath the ship. The number and location of the pontoons, andthe manner and degree to which they are rendered buoyant during variousstages of the ship-raising operation, depend upon the attitude andorientation of the ship in its sunken position, the extent and nature ofthe damages to the hull which caused its sinking, and the manner and thedistance through which the ship is to be towed after being raised.

In the present instance, by Way of illustration, it will be assumed thatit is desired to tow the raised ship in upright position and that alarge part of the required buoyancy can be contributed by the hull ofthe ship after temporary repairs thereto. It will also be assumed thatthe sunken ship lies somewhat on its side, as shown. Accordingly,initially it is desired to produce more buoyancy in the pontoons on thelow side of the ship than on the high side, so as to turn the ship intoupright position. With the salvaging rig of the present invention, suchoperations can be carried out completely from the surface of the water.

Since lifting devices 31 will engage the ship substantially withoutslip, the degree to which the ship has been turned may accurately begauged by the travel of the upper ends of lifting members 31 through therespective fastening means 32, 32' therefor, it being understood thatthe connections at 32, 32 are constantly taken up or let out as theposition of the ship changes. After the ship has been turned intoupright position, it may be lifted from the bottom by blowing the waterto various degrees from the several pont-oons so as to give the assemblyof pontoons and ship the required buoyancy. During all these operations,the attitude or orientation of the ship both laterally andlongitudinally is apparent at all times from the length of the variouslifting devices and/or drawlines extending upwardly from connections 32,32' at the secondary bridles.

It is assumed that the character of the damage to the ship has alreadybeen surveyed and that a temporary patch, which may be of the pneumatictype, to seal the opening 15 in the hull thereof has been made and isready. As the ship nears the surface, the prepared patch, showndiagrammatically at 35 in FIG. 4, may be applied and sealed thereto.After this, buoyancy may be given the hull without any other operations,once the upper hatch covers of the hull have emerged from the Water,merely by pumping the Water from the hull. Should it be desired toutilize the added buoyancy of the hull which is potentially availablewhile it is still an appreciable distance under water, this can be done,once the hull has been raised to a level at which divers may normallywork for extended periods, by sealing as by welding the various hatchcovers of the hull as well as applying the patch 35 when the ship isstill under water at that level.

Turning now to the detailed construction of the cablelaying apparatus24, the shape of such tool in side elevation is dictated by the shape ofthe cross section of the object to be raised. Thus, for the operationdescribed, the tool is: made generally symmetrical and of a broad V or abroad U-shape, having a depth suflicient to extend below the ship at itsgreatest depth, and having a width at its upper end such that thebranches or legs of the apparatus lie spaced from the object at itsgreatest width. The apparatus 24 will ordinarily have been assembledfrom a plurality of sections after a survey of the object to be raised.In addition to the above requirements, it is ordinarily preferable thatthe legs of the apparatus be of suflicient length so that their terminalmembers 40 lie above the upper level of the bottom :11 upon which theobject lies. I

The apparatus 24 as shown has two oppositely disposed bottom sections 36joined at an apex 37, the upper ends of sections 36 having extensions 39connected thereto. The above mentioned terminal fittings 40, at theupper end of each section 39, house joints (not shown) between theseparate hose members 42 in the multiple flexible hoses 25 and tubes, tobe described, supplying each of the sections of apparatus 24 withdredging fluid under pressure. The apparatus 24 is preferably subdividedinto a number of compartments longitudinally thereof, each compartmenthaving its separate dredging fluid supply. The tool shown is laterallysymmetrical. The portion thereof shown in FIG. 7 is typical of theconstruct-ion of the compartments therealong. In the portion of the toolshown in FIG. 7, there are three subsections 44, 45, and 46, which arejoined together in forming the tool. The joint between sections 44 and45, which is typical of the joints, except that at the apex, in thetool, is formed by partitions 49 on the respective sections, thepartitions having outwardly directed flanges 49", the flanges beingsealed by gaskets and joining studs 56, as shown. Apex joint 37 may beformed, for example, by welding the abutting sections together. The sidewall of each of the tool sections is provided with a plurality ofjet-forming orifices 50, as shown in FIG. 7. Orifices 50 are preferablyso disposed as to slant upwardly and outwardly so as to displace the mudand silt of the ocean bottom in that direction when fluid under pressureescapes from such orifices. The sections of the tool are divided bytransversely extending partitions there being a partition 59 shown atthe apex 37, two generally equally spaced intermediate partitions 56 and57 in section 44 and a somewhat similar partition 55 in section 45.Either one or both of flanged members '49 also functions as a partition.

Each of the thus formed compartments 51, 53, 58, 52, 54, etc., in thetool is fed by its respective conduit extending longitudinally of thetool and connected at its outer end to an appropriate one of the hoses42. The pipes 69, 61, 61, 62, etc., which serve the various compartmentsof the tool are arranged in the manner more clearly shown in FIG. 6. Thecentral pipe 69, for example extends through all the transversepartitions and is welded thereto, terminating at its inner end withinthe sub-compartment 54. To aid in the distribution of fluid from conduit6% throughout compartment 54-, partition 59 is provided with a generallyconical projection 64 confronting the orifice of the conduit.

Others of the pipes extend sequentially through and are sealed as bybeing welded to the various transverse partitions, each conduitterminating in the particular compartment which it is to serve. Thevarious hoses 42, which are connected to the respective conduits ofwhich those shown at 6tl62, inclusive, are exemplary, are disposed inthe flexible hoses 25, and lead to pumping apparatus on the respectivetender 22. A separately operated valve, not shown, is associated witheach such hose on such tender, whereby the rate of flow of dredgingfluid, such as water, under pressure to each sub-compartment of thedredging apparatus may be separately regulated.

During operation of the apparatus 2t, its various compartments aresupplied With fluid such as Water in the required amounts. Such fluid,escaping from orifices 50, in combination with the Weight of the tool,initially cause the tool to sink and/or bite its way into the oceanbottom in a position in alignment with the ship. Thereafter, thewinching devices on the tenders 22 draw the tool slowly through theocean bottom, the tenders keeping pace with apparatus 24. The amount oftension in the draw cables 26 required to move apparatus 24- is no morethan that well within the capabilities of ordinary winching apparatus,due to the cutting action exerted upon the ocean bottom by the jetsissuing from orifices 50.

The tool 24, which is thus propelled through the ocean bottom beneaththe object to be raised, makes possible the laying or drawing in, atvarious positions longitudinally of the ship, of drawlines and/ orlifting cables and chains. In the embodiment shown, there are disposed aplurality, four shown, of tube-like guide members 66 which are disposedlongitudinally along the upper edge of tool 24 in the manner shown inFIG. 6. In the embodiment shown, the flanges 49' are cut out on the topthereof, at a zone 65, to provide a space within which members 66 arereceived. The construction of members 66 and the nature of the bundlesor packs of drawlines contained therein will be more readily appreciatedfrom a consideration of FIG. 8.

7 As there shown, the tube 66 has a longitudinally extending slot 67 inthe upper wall thereof, the slot being of a width but little exceedingthe diameter of each of the drawlines 69 contained within tube 66. Thedrawlines are preferably initially held in a bundle or pack form,

being secured together by a plastic material such wax or tar. Thus thedrawlines and their matrix of plastic material may be charged as a wholeinto the guide 66. The pack or bundle of drawlines will have beencarefully assembled and oriented in guide 66 so that the drawlines maybe removed from the member 66 through the slot 67 in a designatedsuccession without any danger of entangling the drawlines with eachother. Thus, after the tool 24 has reached a certain location beneaththe ship, assuming that it is desired to deposit a drawline thereat, itis necessary only to exert tension upon the opposite ends of thedrawline next to be withdrawn, so that the drawline passes radiallyoutwardly through slot 67 and may be drawn upwardly partially to embracethe ship. Following this the opposite ends of the drawline are securedto the surface rig, as for example, to secondary bridles 30, 30'.Conveniently, the drawlines are of such length as to extend betweentenders 22 when such drawlines are in devices 66, so that alldrawline-laying operations may be conducted from the tenders.

The means for drawing in the lifting cables or chains are somewhatsimilarly disposed along the bottom of tool 24. As shown in FIG. 6,there are three tubular guide members 72 disposed longitudinally of thetool, the guide members fitting within aligned pockets 71 provided inthe flanges 49' joining sections of the tool. Each of tubes 72 has alongitudinally extending slot 74 therein, there being a travellingrunner or shoe 75 fitting within tube 72. Projecting in a radial planefrom body 75 is a vane-like member 76 which provides a means ofattachment of either a lifting chain 84 to be drawn in beneath the shipor a lifting cable 85 for the same purpose. The shoe 75 is provided withconical end portions 79 to which are attached eyes 80. Oppositelyextending draw chains 81 are attached to rings 80 and extend along thetubes 72. Draw chains 81 are of sufiicient length so that each has itsouter end, provided with a ring 82, extending upwardly beyond the upperend of the respective tube 72 and to the respective tender 22. Thus thepersonnel on the two tender vessels 22 may readily cooperate to draw oneof chains 81 while releasing the other, so that either a draw chain or adraw cable may be pulled into place beneath the ship 10.

The vessel is assumed in this example to be lifted by lifting chains 84.The construction of the pontoons 34, of the chains 84, and of theirselectively operable means for attachment to pontoon 34 will be morereadily understood upon consideration of FIGS. and 11. The pontoon 34,as shown, is provided with the usual lashing rings 86 by which it may bemanipulated. The pontoon is provided with a valve port 87 and with aselectively positionable valve member 89 so as to open or close theport. Port 87' is employed both as an inlet and an exhaust for admittingwater into or exhausting it from the pontoon. The valve member 89 isunder the control of a hydraulic or pneumatic motor 90, and is normallyurged into valve-closed position by a coil tension spring 91. Motor 90is provided with two ports 92 and 94, connected to sources of pressureto hoses, not shown, leading to the tender vessel. When port 92 issubjected to pressure and port 94 is opened to the atmosphere the valveport 87 is opened. When valve port 92 is connected to the exhaust andvalve port 94 is connected to pressure, the port 87 will close. Thepontoon is provided with an air inlet pipe 95 connected by a hose 96 toa source of air under pressure, as for instance to pumping apparatus onone of the tenders. By proper manipulation of the source of air pressureleading to hose 96 and of valve port 87', the pontoon 34 may be giventhe desired buoyancy at any time. Preferably port 87' is so locatedvertically of the pontoon that when the water in the pontoon isexhausted to the level of such port, the pontoon will have apredetermined buoyancy. In order to allow the further exhaustion ofwater from the pontoon, the latter is preferably provided at the bottomwith a similar port and surface-controlled valve means therefor. Suchport and valve means are desig nated by the same characters as thosefirst described, but with an added prime.

The pontoon shown is designed to cooper-ate with three lifting chains84. Three longitudinally spaced laterally central passages receiving thechain are disposed in sealed relation to the interior of the pontoon,the passages being formed by tubes extending centrally through thepontoon. The chains 84, in that portion thereof to which the pontoonsare to be selectively coupled, are provided with selectively remotelyoperable dog devices 99 which, when in operative position, couple thechain to the pontoon and, when in inoperative position, allow the chainto pass freely through the passage through the pontoon.

Each dog device 99 has a latch member 100 which is connected at acentral hole 102 to one end of a long link 1101 of the chain 84. Whenlatch member 100 extends across the length of the chain, it spans theend of the passage through the pontoon and thus couples the pontoon tothe chain. Preferably, although not necessarily, the surface of member100 which is to contact the pontoon is provided with a central pilotportion 104 which stably positions it in the end of the passage throughthe pontoon. The end of the next consecutive length of chain is attachedto latch member 160 at a hole 105 which is laterally offset from thecentral hole 102. To one end of the latch member there is attached alatch-opening cable 106 and to the other end of the latch member thereis attached a latch-closing cable 107. Such cables extend upwardlylongitudinally of the chain to a control station at the respectivetender. When the latch member is in its collapsed or inoperativeposition, it and the cables connected thereto extend freely downwardlythrough the respective chain-receiving passages through the pontoon.

The manner of operation of the dog devices will be readily understood bya comparison of FIGS. 10 and 11, in the latter of which the dog devicesare shown in operative position. It will be apparent, that upon thepulling of cable 166, each of the latch devices there shown will beswung to a cross or operative position. The latch devices may beretracted from such operative position by pulling upon cable 167. Thedog devices may selectively be operated to engage either the top orbottom of the pontoon, as required.

To aid in the initial freeing of the ship from the mud or silt in whichit may have settled, the portions of lifting cables 85 which are to lieinitially centrally of and beneath the ship are provided with sheathingin the form of perforated hoses 109 as indicated in FIG. 10. There is nonecessity for such hoses to extend upwardly into the passages throughthe pontoons, since the pontoons are not positioned at any time beneaththe upper surface of the bottom upon which the ship rests. The hoses 109may be connected to a suitable source of pressure, preferably waterpressure, by a supply hose 111 connected thereto by a fitting 110. Thehydraulic pressure may be derived from the same source, that on thetender, that supplies the dredging and cable-laying tool 24. At thebeginning of the lifting operation, and simultaneous with the exertionon the ship of the first large lifting effort by the pontoons 34, thehoses 109 may be supplied with fluid, preferably water, under pressure.This has the tendency to break the vacuum between the ship and the mudor silt of the ocean bottom, thereby markedly decreasing the liftingeffort which the pontoons would otherwise have to exert in the initialpart of the lifting operation.

Although only a limited number of embodiments of the invention have beenillustrated in the accompanying drawings and described in the foregoingspecification, it

is to be expressly understood that various changes, such as in therelative dimensions of the parts, materials used, and the like, as wellas the suggested manner of use of the apparatus of the invention, may bemade therein without departing from the spirit and scope of theinvention as will now be apparent to those skilled in the art.

What is claimed is:

l. The method of salvaging a large heavy object lying on the bottom of abody of water, comprising forming a trench in the bottom below the levelof the object, the trench extending from one side of the object to theother, progressively extending the trench to cause itsinstantaneous'position to travel substantially from one end of theobject to the other, and during the formation and extension of thetrench depositing elongated flexible objectembracing means extendingfrom side to side of the object in the trench beneath the object atpositions spaced longitudinally of the object.

2. The method as defined in claim 1, wherein the trench is formed andextended by a laterally extending bottomcutting tool, and the elongatedobject-embracing means are deposited in the trench at the location ofthe cutting means.

3. The method as defined in claim 2, wherein the object-embracing meansare adapted to lift the object.

4. The method .as defined in claim 2, wherein the ob ject-embracingmeans are drawlines, and comprising drawing elongated flexibleobject-lifting means beneath the object by the drawlines.

5. The method as defined in claim 1, wherein the material of which thebottom is composed is relatively soft, and comprising forming the trenchby directing a plurality of streams of fluid under pressure outwardlyagainst the material of the bottom from an elongated laterally disposedsource of fluid under pressure, and causing the instantaneous positionof the trench to travel longitudinally of the object by moving thesource of fluid pressure and the streams of fluid longitudinally beneaththe object.

6. The method of salvaging a large heavy object lying on the bottom of abody of water, comprising forming a trench in the bottom below the levelof the object, the trench extending from one side of the object to theother, progressively extending the trench to cause its instantaneousposition to travel substantially from one end of the object to theother, during the formation and extension of the trench depositingelongated flexible object-embracing means extending from side to side ofthe object in the trench beneath the object at positions spacedlongitudinally of the object, positioning a longitudinally extendingbridle line at the surface of the water along each side of the object,and securing the ends of the objectembracing means to the respectivebridle lines.

7. The method as defined in claim 6, comprising positioning thelongitudinal bridle lines by buoys anchored to the bottom.

8. The method as defined in claim 7, comprising positioning by buoysanchored to the bottom laterally extending bridle lines at the surfaceof the water beyond the ends of the object, the longitudinal bridlelines being secured to the lateral bridle lines.

9. The method as defined in claim 2, wherein the bottom-cutting tool ismoved by cable means attached to the ends of the tool.

10. The method as defined in claim 9, wherein the cable means are guidedat the respective sides of the object whereby the tool moveslongitudinally of the object.

11. A rig for salvaging a large heavy object lying on the bottom of abody of Water at a depth substantially beyond that at which divers maynormally work for extended periods, comprising an elongated,trench-forming tool adapted to be introduced into the material of thebottom to lie beneath the object, the tool being adapted to form atrench extending beneath and laterally beyond the object andprogessively to cause the instantaneous position of the trench to travellongitudinally of the object upon movement of the tool longitudinally ofthe object, and means attached to the tool for depositing elongatedflexible object-embracing means extending from side to side of theobject in the trench beneath the object at positions spacedlongitudinally of the object.

12. A salvage rig as defined in claim 11, comprising means for movingthe tool longitudinally of the object.

13. A salvage rig as defined in claim 11, wherein the trench-formingtool comprises a conduit having a plurality of orifices in its sidewall,and means to supply the interior of the conduit with fluid underpressure whereby to form material-displacing jets at the orifices.

14. A salvage rig as defined in claim 13, wherein the orifices in thewall of the conduit generally on the respective sides of the midpoint ofthe length of the conduit are inclined radially outwardly and toward therespective outer ends of the conduit.

15. A salvage rig as defined in claim 13, wherein the conduit isprovided with a plurality of serially arranged compartments, andcomprising means separately to control the flow of fluid under pressureto the compartments.

16. A salvage rig as defined in claim 15, comprising a plurality offluid supply pipes within the conduit, the pipes being connected to asource of fluid pressure at an outer end of the conduit, the pipesterminating at their inner ends in the respective compartments whichthey supply.

17. A rig for salvaging a large heavy object lying on the bottom of abody of water at a depth substantially beyond that at which divers maynormally work for extended periods, comprising an elongated,trench-forming tool adapted to be introduced into the material of thebottom to lie beneath the object, the tool being adapted to form atrench extending beneath and laterally beyond the object andprogressively to cause the instantaneous position of the trench totravel longitudinally of the object upon movement of the toollongitudinally of the object, and means for depositing elongatedflexible objectembracing means extending from side to side of the objectin the trench beneath the object at positions spaced longitudinally ofthe object, the tool having an elongated casing, and the means fordepositing flexible objectembracing means in the trench comprising anelongated open-sided guide secured to and extending longitudinally ofthe casing.

18. A salvage rig as defined in claim 17, wherein the guide has atube-like body and is located on the top of the casing, and there is alongitudinally extending narrow slot in the upper side of the body.

19. A salvage rig as defined in claim 18, comprising a plurality ofrelatively thin flexible drawlines disposed in parallel relationship inthe tube-like body and adapted for sequential withdrawal therefromgenerally radially outwardly through the slot.

20. In an underwater salvage rig, a holder and dispenser for a pluralityof drawlines comprising an elon gated tube-like body adapted to bedisposed across an object to be engaged by one or more drawlines, saidbody having a longitudinally extending narrow slot in the wall thereof,and a plurality of relatively thin flexible drawlines disposed inparallel relationship in the tube-like body and adapted for sequentialwithdrawal therefrom generally radially outwardly through the slot.

21. A drawline holder and dispenser as defined in claim 20, comprisingan adhesive material for temporarily holding the drawlines together as agroup in the body, the adhesive material yielding to allow thesequential withdrawal of drawlines from the group.

22. A salvage rig as defined in clam 17, wherein the guide is located onthe bottom of the casing, the open side of the guide is located adjacentthe bottom thereof, and comprising a shoe-like runner adapted to bepulled along the guide therewithin, said runner having a fin adapted toproject outwardly through the open side of the guide, the fin havingmeans adjacent its outer end for the attachment of an elongated flexibleobject-lifting means whereby the last named means may be drawn intoobject-embracing position by the runner.

23. A salvage rig as defined in claim 17, wherein the casing is in theform of a portion of a loop and is adapted to pass through the materialof the bottom in a path spaced from the bottom and sides of the object.

24. A salvage rig as defined in claim 23, comprising means at both endsof the tool for supplying it with fluid under pressure, and means at theends of the tool for drawing it beneath the object.

References Cited in the file of this patent UNITED STATES PATENTS AdamsSept. 18, 1877 Midford Dec. 1, 1896 Arbuckle Mar. 3, 1903 Cummings etal. Dec. 29, 1903 Serres Aug. 29, 1911 Tognacci Apr. 29, 1919 DawsonMar. 1, 1921 Jensen et al. Feb. 25, 1958

